Areas where methane bubbles up from seafloor have been around for centuries.

The earth sciences have described a number of processes that are decidedly unpleasant for any living organisms unlucky enough to experience them, from volcanic eruptions to mass extinctions. Climatic “tipping points” are one of those scary processes. You can think of them along the lines of a kid who accidentally crests a steep hill on an old bike with no brakes—he won’t be stopping before the bottom of the hill (or he wipes out, whichever comes first). Crossing a tipping point in the climate system means being locked into some magnitude of climate change with no chance of halting it.

One scary tipping point involves the methane locked in molecular cages of ice called clathrates (or methane hydrates), found within the sediment on the seafloor. Heating up the water enough to melt hydrates and release methane adds an additional punch of greenhouse warming to whatever caused the heating. Such heating has been implicated in some ugly climate swings in Earth’s past.

Climate scientists don’t anticipate crossing this tipping point any time soon (the latest IPCC report judged it “very unlikely” this century), but that doesn’t mean hydrates aren’t the focus of research and concern. There is still much we don’t know about where hydrates are present and how much ocean warming it takes to begin destabilizing them.

Recent discoveries of areas in which methane is literally bubbling up from the seafloor around the Arctic have stoked worries that we could be closer to hitting this tipping point than we thought. But since we’ve only been observing them for such a short time, there’s been no way to know if those bubble plumes are new and worrisome or just the millennia-old status quo. A new paper in Science provides a little information about the history of the methane bubbling up around the Arctic islands of Svalbard, north of Scandinavia.

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As organic matter in the sediments around Svalbard decays, methane is produced. Where the pressure is great enough (because of the water depth) and the temperature is cold enough, methane hydrates can form. At the shallowest edge of that zone where hydrates can exist, it doesn’t take much of a change to make them unstable. Because of the currents around Svalbard, the water there has warmed more rapidly than most of the rest of the Arctic Ocean—bottom water temperatures have risen about one degree Celsius over the past 30 years.

Plumes of rising methane bubbles have been mapped off the coast of Svalbard to where the water is about 400 meters deep—the edge of the stability zone for hydrates. In order to find out if these plumes are the result of that recent warming or are simply a feature of the area, a team of researchers led by Christian Berndt of Germany’s GEOMAR Helmholtz Centre for Ocean Research Kiel used a submersible to get a look at the seafloor where the methane is bubbling up.

There, they found crusts of calcium carbonate formed by bacteria living off the methane. (In fact, there were communities of chemosynthetic bacteria and a kind of tubeworm living at all the methane seeps they visited.) The age of geologically recent, precipitated carbonate in the ocean can be measured using radioactive isotopes of uranium and thorium, so these crusts provided a record of how long methane had been bubbling up at these spots.

The carbonate turned out to be much older than anthropogenic climate change, with measurements dating them anywhere from 500 years to over 8,000 years old. That means that, at least in the locations they sampled, methane has been bubbling for quite a long time.

The researchers also made measurements of seasonal water temperature variation and the ability of the sediment to conduct heat, which they used to create a model of the study area. The model showed that there should be a seasonal cycle in the behavior of the shallow-water hydrates just below the seafloor, with some additional hydrates forming while the water temperature is cooler and then melting when the water is warmer. That process could affect the total rate of methane coming up by clearing out pathways to the surface during the warmer part of the year.

The study allays concerns that these bubbling plumes of methane around Svalbard are a brand-new phenomenon triggered by global warming, but it’s still unknown if the rate of bubbling is changing. The researchers summarize their work by writing that “observations of large contemporary emissions reported in other studies cannot be considered proof of accelerating hydrate destabilization, although neither do they prove that catastrophic destabilization is not accelerating.” Figuring that out will simply take continued monitoring and a better understanding of the conditions on the Arctic seafloor.

Yeah, it would be great to have a handle on the rate and sensitivity. OTOH in a sense it is kind of moot, even without a CH4 catastrophe we're still pretty much going to have to go to the hilt on decarbonizing the economy. It would be great to know that there is a catastrophe which isn't going to happen, but its only one of a lot of different processes we want to avoid.

Even though it is very interesting, this is not the way to write about climate science. We all know that no one actually uses careful observation, patient data gathering and reasoned, non-hysterical analysis.

You are SUPPOSED to make stuff up and scream alarming headlines.

Better straighten up before you get kicked out of the global conspiracy. You could lose your secret decoder ring!

When alarmists talk about global warming, they are refering only to the temperature of the atmosphere, which is a very tiny fraction of the whole mass of the planet. It is absurd to call that "global warming". The planet as a whole has been cooling ever since it was glowing red hot 4.5 billion years ago and will continue to do so regardless of what we insignifcant humans do or don't do.

When alarmists talk about global warming, they are refering only to the temperature of the atmosphere, which is a very tiny fraction of the whole mass of the planet. It is absurd to call that "global warming".

Next, you can tell us how a double-negative doesn't not make a positive.

When alarmists talk about global warming, they are refering only to the temperature of the atmosphere, which is a very tiny fraction of the whole mass of the planet. It is absurd to call that "global warming". The planet as a whole has been cooling ever since it was glowing red hot 4.5 billion years ago and will continue to do so regardless of what we insignifcant humans do or don't do.

When alarmists talk about global warming, they are refering only to the temperature of the atmosphere, which is a very tiny fraction of the whole mass of the planet. It is absurd to call that "global warming". The planet as a whole has been cooling ever since it was glowing red hot 4.5 billion years ago and will continue to do so regardless of what we insignifcant humans do or don't do.

I know can you believe people actually think there could be some kind of consequence to spewing garbage and pollution into our environment.

As long as it's just swept neatly under the rug we'll all be fine.

God obviously created enough buffer that no matter how much garbage we pile up for however many years that it will just disappear into the ocean.

When alarmists talk about global warming, they are refering only to the temperature of the atmosphere, which is a very tiny fraction of the whole mass of the planet. It is absurd to call that "global warming".

It's true that the surface temperatures have been getting a lot of focus and that the heat content of the oceans is important to understand the climate system. That's why we've also been studying OHC. It also shows a warming trend, even in recent years when the surface temperatures started to slow down a bit. http://www.nodc.noaa.gov/OC5/3M_HEAT_CONTENT/http://www.skepticalscience.com/graphics.php?g=65When the land masses, atmosphere, and oceans are all considered together, we've been building up additional energy in the climate system at the rate of about 4 Hiroshima bombs per second, which averages out to about 2 billion detonations' worth of energy since 1998 alone. That's not energy which just dissipates, that's the energy that's constantly being accumulated in the climate system, which is what drives those lines and graphs upwards over the years.

When alarmists talk about global warming, they are refering only to the temperature of the atmosphere, which is a very tiny fraction of the whole mass of the planet. It is absurd to call that "global warming". The planet as a whole has been cooling ever since it was glowing red hot 4.5 billion years ago and will continue to do so regardless of what we insignifcant humans do or don't do.

Guess what, the atmosphere is where we live. I'm not too concerned about the temperature of the mantle. Also, for many years now it's been referred to, outside the popular press, as climate change, not global warming.

When soldiers talk about snipers, they are refering only to the mass of the individual bullets, which is a very tiny fraction of the whole mass of the weapon. It is absurd to call that "highly lethal".

Another factor to add to those complex models I guess! Amazing that climate models can supposedly and accurately simulate past climate and not have factored in such a massive influential factor!

As a pro-environment/anti-pollution activist, I'm becoming a AGW denialist.

Wow! Your second post.

I would have bet so much that this was the first one.

Gee, thanks. I've been reading ARS for years. Recently registered so I can point out some of the contradictions in the conclusions many of the very intelligent folks here stand on so firmly.

Don't take it personally.

Its just very common to see post like yours coming from people who make a climate change related post as their first one. I was honestly (!) suprised to that it was you 2nd post. Made me wonder, if they had started paying extra for making a honest looking post before starting the astroturfing flood.

Wheels et al. will point out the flaws in your argument anyway. I'll just continue with my friday night beers.

Another factor to add to those complex models I guess! Amazing that climate models can supposedly and accurately simulate past climate and not have factored in such a massive influential factor!

As a pro-environment/anti-pollution activist, I'm becoming a AGW denialist.

Wow! Your second post.

I would have bet so much that this was the first one.

Gee, thanks. I've been reading ARS for years. Recently registered so I can point out some of the contradictions in the conclusions many of the very intelligent folks here stand on so firmly.

Unfortunately, the contradiction you are pointing out turns out not to exist. This isn't even a remotely hard argument. As Wheels pointed out, what we are talking about is clathrate melting, which is a potential future danger, not something that is a major climate factor right now. So, as far as what the models use, this changes nothing, since the models don't assume any large-scale clathrate melting has already occurred, and this just confirms that that is indeed the case.

I.e. this is confirmation of how the models treat the past and present of clathrate dynamics, so this has no impact on the evidence for climate change.

Even though it is very interesting, this is not the way to write about climate science. We all know that no one actually uses careful observation, patient data gathering and reasoned, non-hysterical analysis.

You are SUPPOSED to make stuff up and scream alarming headlines.

Better straighten up before you get kicked out of the global conspiracy. You could lose your secret decoder ring!

Actually most of the alarm comes from careful observations. Most of the invention and screaming comes from people turning tricks for Kochbucks.

Another factor to add to those complex models I guess! Amazing that climate models can supposedly and accurately simulate past climate and not have factored in such a massive influential factor!

As a pro-environment/anti-pollution activist, I'm becoming a AGW denialist.

I would say I am sorry to pile on, but I am not. Methane content of the atmosphere is built into the models, and where it came from, farting cows, clathrates, or volcanic activity really does not matter. It is what it is. It also has a relatively short half life of ~100 years in the atmosphere, so as it is discharged into the atmosphere, it slowly disappears. Whether some sources may add dramatically to the rate of addition in the future is the issue with clathrates, which actually contain a huge metastable reservoir of methane. Now that it has been explained to you, you can return to your pro-environment/anti-pollution activist roots and ignore the shallow AGW denialist siren song.

Are there other ways we determine the composition of the air in the past other than ice core samples? My concern is that methane gas is temperature dependent as to when it's heavier and lighter than air and may skew results.

I'm not even going to pretend to know much about this but we now know that there has been a lot of "methane bubbling" in the past and I wonder how well we are capturing the concentration levels.

Are there other ways we determine the composition of the air in the past other than ice core samples? My concern is that methane gas is temperature dependent as to when it's heavier and lighter than air and may skew results.

I'm not even going to pretend to know much about this but we now know that there has been a lot of "methane bubbling" in the past and I wonder how well we are capturing the concentration levels.

Carbon isotopes can get us information about CO2 and CH4 in the atmosphere. The atmosphere mixes, so the distribution of methane in the troposphere shouldn't change with temperature.

Another factor to add to those complex models I guess! Amazing that climate models can supposedly and accurately simulate past climate and not have factored in such a massive influential factor!

As a pro-environment/anti-pollution activist, I'm becoming a AGW denialist.

I would say I am sorry to pile on, but I am not. Methane content of the atmosphere is built into the models, and where it came from, farting cows, clathrates, or volcanic activity really does not matter. It is what it is. It also has a relatively short half life of ~100 years in the atmosphere, so as it is discharged into the atmosphere, it slowly disappears. Whether some sources may add dramatically to the rate of addition in the future is the issue with clathrates, which actually contain a huge metastable reservoir of methane. Now that it has been explained to you, you can return to your pro-environment/anti-pollution activist roots and ignore the shallow AGW denialist siren song.

Just one note- methane lifetime in the atmosphere is about 12 years. By then it reacts with OH radicals to make water and a couple CO2 molecules.

Another factor to add to those complex models I guess! Amazing that climate models can supposedly and accurately simulate past climate and not have factored in such a massive influential factor!

As a pro-environment/anti-pollution activist, I'm becoming a AGW denialist.

I would say I am sorry to pile on, but I am not. Methane content of the atmosphere is built into the models, and where it came from, farting cows, clathrates, or volcanic activity really does not matter. It is what it is. It also has a relatively short half life of ~100 years in the atmosphere, so as it is discharged into the atmosphere, it slowly disappears. Whether some sources may add dramatically to the rate of addition in the future is the issue with clathrates, which actually contain a huge metastable reservoir of methane. Now that it has been explained to you, you can return to your pro-environment/anti-pollution activist roots and ignore the shallow AGW denialist siren song.

Just one note- methane lifetime in the atmosphere is about 12 years. By then it reacts with OH radicals to make water and a couple CO2 molecules.

That's 12.4 year half life. Methane remains a very potent greenhouse gas over the century time-frame we and our kids have to solve this problem.

Another factor to add to those complex models I guess! Amazing that climate models can supposedly and accurately simulate past climate and not have factored in such a massive influential factor!

As a pro-environment/anti-pollution activist, I'm becoming a AGW denialist.

I would say I am sorry to pile on, but I am not. Methane content of the atmosphere is built into the models, and where it came from, farting cows, clathrates, or volcanic activity really does not matter. It is what it is. It also has a relatively short half life of ~100 years in the atmosphere, so as it is discharged into the atmosphere, it slowly disappears. Whether some sources may add dramatically to the rate of addition in the future is the issue with clathrates, which actually contain a huge metastable reservoir of methane. Now that it has been explained to you, you can return to your pro-environment/anti-pollution activist roots and ignore the shallow AGW denialist siren song.

Just one note- methane lifetime in the atmosphere is about 12 years. By then it reacts with OH radicals to make water and a couple CO2 molecules.

That's 12.4 year half life. Methane remains a very potent greenhouse gas over the century time-frame we and our kids have to solve this problem.

It's not a half-life, it's the average time a molecule lasts before reacting. It's not an exponential decay.

The 100-yr CO2 equivalent multipliers are based on total energy absorbed by methane and the CO2 it breaks down into during that timeframe.

When alarmists talk about global warming, they are refering only to the temperature of the atmosphere, which is a very tiny fraction of the whole mass of the planet. It is absurd to call that "global warming". The planet as a whole has been cooling ever since it was glowing red hot 4.5 billion years ago and will continue to do so regardless of what we insignifcant humans do or don't do.

Yeah, you're sooooo right -- it would be really, really dumb, to worry about changes that affect only the parts of the planet where we actually live.